I need to know if anyone has had this situation before with a Volare clip so I can diagnose the problem

Here's what I have: '63 shortbox Uni with a volare clip BOLTED on the bottom modifed/boxed frame. Ride height only about an inch of two lower than stock.
There are big rubber mounts approx 1"-1-1/2" thick between the frame and the k-member where it bolts on, in 4 places.

Here's the problem: Truck bump steers when the weight shifts to the right or the left something awful. Just like steering a skateboard. Takes off in the opposite direction the weight is shifted on in a turn.

Here's what it feels like: 1) maybe the steering box is worn and there's enough slop to just turn the wheels by themselves
2) maybe it IS steering like a skateboard on those big rubber mounts. Bolts are tight, they dont seem loose enough to cause that. Long shot.
3) Another longshot-maybe the rear spring bushings are worn enough that the back axle actually turns when I turn and the rear axle is steering..?
4) Ball joints maybe worn? Will they cause this?

Anyway, anyone who has experienced this, please drop a line. Too many factors to chase down here without input from someone else who has been there.

RF

 

Ringo,
Steering is a matter of foot print transplant done through modifcation of the laws of physics.
In other words what you attempt to do as you steer is "project" forward motion, and all it's kinetic energy, around a curve or turn ahead of where you are when you start. The laws of physics are not rewritable and tend to remain fairly constant. However it is possible to fudge within physics' matrix by applying other laws of physics. In short, bend the trajectory of mass in motion by aiming ahead of a point you are at. Sort of "Planning ahead". . . .

You can't simply turn wheels to the left or right expecting velocity to change with it. The 3 factors involved in front end geometry are caster, camber and toe in. IOW front end alignment specs. In an OEM applications factory engineers determine these specs by their design of steering components and their relative functional geometry.

In a "K" member, the plane of your upper and lower, inner control arm pivots has to be equal to the plane of a unit when it was in the donor you got it from. When front inner pivots are higher or lower than their relative OEM position, or to each other. The plane thru these pivots will impact caster Nd camber as Control arms flex or wheels are turned in or out to steer. If they are not coincidental, or similar to OEM positions, that can create bump steer because the theoretical geometric center flucuates when the parts are in motion.

I don't know for a fact, but I'd presume your upper inner control arm shafts are the cause of your problem. They most likely are not at an OEM angle because the plane of yout "K" frame could be slightly off OEM angle also. Chances a bottom of a FoMoCo Straight axle based chassis having a similar angle or inclination as Aspen-Volare where the "K" frame bolts up is slim to none. Most folks don't know enough to replicate the OEM mounting angle when swapping such front end components between brands.

I know resolving bump steer in a street rod is fairls easy as long as the things are oriented so they can function. I have seen a lot of grief from M-II IFS being welded in incorrectly, or subframes mounted in a non compliant angle to the OEM requirements.
Another cause can be just from having any of the front end out of adjustment or as you suspected excessive wear, which can cause adjustment problems.

To prove me wrong, see if you can measure front & rear inner control arm shaft end hieght on a stocker. Tf they're the same, your inner shafts must be also, or else the std OEM settings, and/ or design will conflict and not work right.

Conversely if the OEM shaft heights are different (front to rear) your shafts should have the same difference in end height.

In functional front ends, as wheels turn in a direction a greater difference between a wheel turning outward and one turning inward occurs. Without that difference the forward motion will begin to fall over the inward turning wheel, and not respond to the outwarsd turning wheel, or vice-a- versa depending on whether difference is + or - to the prescribed OEM settings.

I hope this helps to understand steering basics & solve your bump steer problem too.

FBp

 

Wow, Pete that is a whole lot of good information, too much for my mosquito brain to absorb in one chunk. Not that I don't appreciate your help, you are a man of great wisdom, and I thank you.

This work was not done (obviously) by myself but rather by the PO. He did make some attempt to configure the frame in a fashion that would hold the K member at an angle similar to the original car, the bottom of the fram is at a different angle than stock. Also, when I took the truck for a wheel alignment, they set it to OE Volare specs for caster and camber, whether or not that make any difference whatsoever I do not know. I do not have an OE car handy to measure the required things, on my next trip to the boneyard I will make that attempt, tho.

Again, thanks. Anybody who has cured a similar problem on thier truck want to pipe up?

RF

 

Inspect the frame cross members. All must be tight with good rivets or tight bolts (frame flex). Check the rear springs, spring shackles, spring pivot bushings and U bolts. I'd lose those rubber bushings and replace them with solid spacers. Plus all of what FBp said.

 

Ringo I have a bolted in volare clip also. My front mounts are flush to the bottom of the frame and the rear mounts are spaced about 2" below the bottom of the frame. I can take some pics and post in my gallery but it will have to be next week. If you could get some pics of the mounting arrangement front and rear in your gallery we could take a look and come up with a solution. Sounds to me like the rear of the volare clip has to be lowered some. and then it will need to be realigned.

 

Ringo,
Try setting it to specs for a twin I beam type frame with about same wheel base as you have, +/- a few inches.
What we're trying to achieve is focusing theoretical wheel centers to actually cross each other way out ahead of the vehicle at some prescribed distance, that is what Toe -In is all about.

Caster's about making wheels follow or track behind loads' vertical pivot center, that
would be a vertical line thru kingpin/ ball joint centers, about which rotation occurs when executing a turn. If you ever had a shopping cart with a wheel that wiggles or waggles from side to side if you push to fast, that's an example of want a bad caster setting does. The errant wheel can't find it's own dynamic center so it can't follow it, it seeks a center instead, by going from side to side. Think of caster as the vertical center in the lognitudinal palne (front to rear, or along the line of travel).

Camber, is the inclination of the vertical pivot centers in the Lateral plane, or across the line of travel, as in side to side. Camber is what causes tops of outturned wheels to lean outward & in turned wheels to lean inward. It's camber preventing vehicle from running over an inturned wheel or ignoring an out turned one, as mentioned above in my 1st post of this thread.

With caster and camber together, a theoretical point of intersection, ahead of vehicle I said toe in gives us, will change distance as wheels are turned across the steering range, left to right or vice-a-versa. the harder the steering is cramped to a side, the closer the intersection occurs. When a vehicle is dead ahead, or straight forward this throretical intersection is tha farthest from the vehicle.

When a front end is correctly set these imaginary lines create an equallateral triangle, the apex of which should be dead center of the vehicles' mass. As the steering is engaged the triangle makes a transition from equallateral to scalene of the side to which the steering wheel is turned. Turning the opposite direction simply returns that scalene triangle back through equallateral to a mirror or reverse scalene, albeit right or left. If the equallateral triangle isn't falling at the center of mass, the forward motion of the vehicle will be to pull to the side, the apex of this imaginary "triangle" falls on.
Conversely, when the apex of an equallateral triangle occurs too close or too distant
from its' base (a lateral centerline drawn horizontal thru spindle centers) the footprint will not transplant because steering never locates/ settles on its' true dynamic center causing you steering mechanisn to "Seek" a center that does not exist correctly for it.

When these 3 things are correctly set, a vehicle will follow that center as steering is changed and moves it. A vehicle will also want to return to straight ahead coming out or off turns at speed.

When one or more of these are wrong, steering is not good.

That's why I'd try the settings for a vehicle with IFS, about the same curb weight and close to the same wheelbase. Do you know how to use a string to verify toe in?
If not contact me and I'll FWD you a paper on that.

FBp

 

I maybe off track here but I had an old unibody that had broken leafs in the rear springs. It sat normal and drove normal with no load. When I went around a sharp corner or a faster one the outside spring would collapse tilting the body way over throwing the front end off and away we would go. It was a bit hairy the first couple a times anyway just a thought.
Jeff

 

You may want to try to set it up OEM aspen/ volare ( Wagon ) they might
be close to the weight of a F-100! Might be close to the same wheel base
as mentioned in prior post.






P.S I'm not sure if the wagons had the adjustable front end, may be worth
looking in to. I think they did come in volare/aspen (Wagon).

 

Many thanks to all who replied here. I will try and snap some pics next time i have a wheel off the front end.
Lots to absorb here, you guys are great!

RF

 

What a trip. {Time warp music and wiggly screen......} My first car was a Plymouth Volare'. I had some good times in that car. 318, auto, primer grey and flat black..... ahhhh and Suzanne. Hmmmm good times, good times..... {Time warp off}

WHY THE HECK WOULD YOU BOLT A VOLARE FRONT END ON A TRUCK!?!?!

(Believe it or not I still have one of the side emblems from that car. Shined up and on one of my memorabilia boards. )

 

Darren....glad to be the proud provider of a blast from the past.

Volare clips are one of the most common replacements for straight axled trucks for not just one but 3 reasons:

1) disc brakes
2) power steering
3) independent front suspension that can be ride height adjusted.

all in one go.

I just wish I knew where to start on this one.... I think it may what cobraguy is saying and the caster needs to be adjusted by lowering the rubber bushings in the front some.
I also noticed that even though it was recently aligned to Volare specs on a computerized alignment machine, the passenger's side tire is wearing a lot more than the driver's, and slightly on the outside of the tire.
Hmmmm.

 

When you run your palm over the wear can you feel a scuff ?
It feels as if you're running your palm across the rough side of a pelt or hide. If the scuff is worse when you move your hand perpendicular to frame, square across the tread surface, that tells ya camber is off. If scuff is rougher when you rub diagonally to the frame across the tread look to toe in.
Computer anything is no better than individual operating it or making adjustments it says need to be done. I've seen many front end/ suspension so called "Specialists" do crummy work.
Generally speaking, caster gives you bump steer, without scuffing. Usually scuffing is result of toe-in or camber maladjustments. You can check toe in/out using a taught dryline, and can check camber with a spirit level. In fact one who is good with front ends and tools can set up & align their front end camber and toe in using these tools. The only one ya can't really, easily, get right is caster, but you can check that with wheels off by establishing the spindle/ steering knuckle center line.

FBp

 

..........

 

Pete. Tire is scuffing with the high side to the frame, perpendicular to the direction of rotation like this

FRAME- __ -OUTSIDE OF TIRE
............\ \_
tread scuff direction
in section


So that is camber?

RF